Problem: Umaima is 72 years old and Kevin is 9 years old. How many years will it take until Umaima is only 4 times as old as Kevin?
Answer: We can use the given information to write down an equation about how many years it will take. Let $y$ be the number of years that it will take. In $y$ years, Umaima will be $72 + y$ years old and Kevin will be $9 + y$ years old. At that time, Umaima will be 4 times as old as Kevin. Writing this information as an equation, we get: $72 + y = 4 (9 + y)$ Simplifying the right side of this equation, we get: $72 + y = 36 + 4 y$ Solving for $y$ , we get: $3 y = 36$ $y = 12$.